The potential energy surfaces for the synthesis and decomposition reaction
of N-8(C-s) --> N-5(+) + N-3(-) and isomerization reaction of N-8(C-s) to N
-8(C-2h) were investigated by density functional theory (DFT). The species
involved were fully optimized using four DFT methods. Relative energies wer
e further calculated at the QCISD/6-311+G*//B3LYP/6-311+G* level. The barri
er heights of Ns(Cs) --> N-5(+) + N-3(-) in forward and reverse directions
were predicted to be 23.4 and 2.0 kcal/mol, respectively. Rate constants fo
r the dissociation and synthesis pathways of Ns(Cs) were found by use of va
riational transition state theory. The barrier height for the isomerization
reaction of Ns(Cs) to Ns(C2h) was predicted to be 4.0 kcal/mol at the QCIS
D/6-311+G*//B3LYP/6-311+G* level.